This invention is directed to handrails for moving walkways, and more particularly, to variable speed handrails.
Prior art variable speed handrails have been unsatisfactory for use in certain environments. For example, they have been found to be unsuitable for use with an accelerating and decelerating moving walkway such as the one disclosed in U.S. Pat. No. 3,939,959, entitled "Accelerating and Decelerating Moving Walkway," by Phillip E. Dunstan et al., because they have not had the ability to accelerate and decelerate by an amount corresponding to the amount of acceleration and deceleration of such a walkway. Prior art handrails are also more complicated than desired. For example, the prior art overlapping handrail system described in U.S. Pat. No. 3,714,902 entitled "Conveyor Handrails" uses a total of three cams and cam followers and a series of hinged linking arms. Rigid members connect each overlapping handrail platform with the linking arms to provide a small increase or decrease in overlap between adjacent platforms. Additionally, a change of orientation of each platform is required when platform overlap increases or decreases. The multiplicity of components required by this and other prior art handrails to create limited acceleration and deceleration of the handrail make these prior art handrails more complicated than desired. This disadvantage becomes even more objectionable as the length of the handrail increases between the entry and exit regions, because a corresponding increase in the number of components is required. Because each complex handrail platform assembly has a potential for mechanism breakdown, increasing the overall length of the handrail and, thus, the number of components increases the potential for handrail failure. In other words, the mean time between failure decreases with length, which decrease is amplified by the complexity of the individual subsystems. Therefore, these systems are not suitable for use over extended distances.
Additionally, it is often desired to place accelerating and decelerating moving walkways and their related accelerating and decelerating handrails in existing building corridors, such as the corridors of an airport terminal, without modifying the corridors. To accomplish this result, it is necessary that the vertical silhouette of the handrail be relatively low and the horizontal silhouette be relatively narrow. In general, prior art handrails cannot meet this requirement. For example, the overlapping handrail described in U.S. Pat. No. 3,714,902, noted above, requires a large area to reverse the direction of the handrail platforms because of the relationship between adjacent rigid members and linking arms. These components interfere with each other unless a large vertical area is provided for reversing the direction of the handrail. As a result, installation of such a prior art handrail in an existing corridor would require that the corridor be modified by excavating a sufficient area to allow the handrail to reverse directions, if the handrail is to have a convenient height for passengers.
Other prior art handrails achieve acceleration and deceleration by a mechanism that is horizontally oriented. The horizontal orientation of these mechanisms create a handrail having a wide horizontal silhouette. This prevents these prior art handrails from being used with moving walkways in existing narrow corridors.
Therefore, it is an object of this invention to provide a new and improved variable speed handrail.
It is a further object of this invention to provide a new and improved variable speed handrail having acceleration and deceleration regions capable of being synchronized with the acceleration and deceleration regions of a moving walkway, such as the moving walkway described in U.S. Pat. No. 3,939,959.
It is yet another object of this invention to provide a new and improved accelerating and decelerating handrail that is relatively uncomplicated and, therefore, suitable for use over extended distances.
It is still another object of this invention to provide a new and improved accelerating and decelerating handrail that is low enough and narrow enough for it to be used with a moving walkway installed in existing corridors.